With increasing concern about declining water resources, there is increasing thrust in improving water management in farming systems to improve water use efficiency. The present investigation was undertaken to determine the optimum timing for the first and last irrigation of cotton on the basis of meteorological approach for scheduling irrigations. The experiment was conducted in a split plot design with three timings of first irrigation as main-plots and three timing of last irrigation as sub-plots. Delay of first irrigation from 28 days after sowing (DAS) to 42DAS, irrespective of last irrigation, resulted in an increase of 8, 14 and 17% in seed cotton yield during first, second and third year, respectively. The corresponding increases due to delay in the last irrigation from 130 to 170DAS were 14, 32 and 8%, respectively. On the basis of 3 years average, application of first and last irrigation at optimum time (after 42 and 170 days after sowing) resulted in an increase of 36% in seed cotton yield without involving any additional cost. Water expense efficiency (WEE) increased by 54%.

A field experiment was conducted for 4 years (1995-96 to 1998-99) at Regional Research Station, Bathinda, Punjab to study the effect of modified furrow irrigation methods on water economy, growth and yield of transplanted gobhi sarson (Brassica napus L. spp oleifera DC. var. annua L.), a canal irrigated area of south-west Punjab. Six methods of irrigation, viz flood irrigation, irrigation to each furrow, irrigation to same alternate furrow, irrigation to alternate furrow irrigated alternately, irrigation to furrow after skipping 2 rows and irrigation to furrow after skipping 3 rows, were compared in randomized block design. The modified methods saved irrigation water compared with flooding method in order of irrigation to furrow after skipping 3 rows > irrigation to furrow after skipping 2 rows > irrigation to same alternate furrow and irrigation to alternate furrow irrigated alternately > irrigation to each furrow. The water economy in these methods was owing to the reduced wetted area in these methods. The differences in growth parameters and grain yield among methods were statistically non-significant. The modified methods of irrigation showed water-expense efficiency of 30.8, 36.7, 46.0 and 54.7 kg/ha-cm water expense with irrigation to each furrow, irrigation to alternate furrow irrigated alternately, irrigation to furrow after skipping 2 rows and irrigation to furrow after skipping 3 rows, respectively, compared with 21.5 kg/ha-cm water expense under flooding method. The modified methods of irrigation may be adopted in enhancing the area under transplanted gobhi sarson compared to flood irrigation method with the considerable saving in irrigation water with little or no loss of productivity.

A field study was conducted for three years ( '1994-95 to 1996-97) on ii1 sandy loam (fine loamy, mixed hypertllermic. ustochreptic camborthic1) soil at the farm of the Regional Research Station, Bathinda to find out the crop sequences suiting the irrigation water available in the region. The mean annual water requirement for post sowing irrigation under cotton-wheat, cotton-barley, cotton-sunflower and cotton-gram were 42.5, 42.5, 70.0 and 32.5 em under optimal regime, and 5.0, 5.0, 27.5, 0.0 em under sub-sub- optimal regime, respectively. BeSides high water requirement, the calion-sunflower sequence gave low economic returns. Wheat in this cotton belt could be replaced by barley under SUb-optimal and by gram under sub-sub- optimal irrigation regime .

Field experiments were conducted for 3 years (1987–8 to 1989–90) at Regional Research Station, Bathinda—a canal irrigated area of the south-west Punjab. The effect of four irrigation methods: flooding, irrigation to each furrow, to alternate furrows and to furrows between paired crop rows, on water economy, growth and yield of Indian rape was studied. Saving by the water-delivery treatments, in comparison with flood irrigation, was in the order: alternate furrows, single furrows between paired rows, every furrow. Alternate furrow irrigation required about 60 percent of the water for flooding but experienced little loss in productivity.

Field experiments were conducted for 3 years (1987-1989) at Regional Research Station, Bathinda, representing a canal irrigated area of southwest Punjab. The effects of four irrigation methods were studied: flooding, irrigation to each furrow, irrigation to alternate furrows, and irrigation to furrows between paired crop rows, on water economy, growth, and yield of cotton. Irrigation water saving by the modified water delivery treatments, in comparison with flood irrigations, was in the order alternate furrows > single furrow between paired rows > every furrow. Alternate furrow irrigation required about 50% of the water required for flooding with little or no loss in productivity.